【摘要】 选用四种不同的分子筛(SAPO-34,ZSM-5,Y,MCM-41)与CuCoMn(高醇合成组元)构成双功能催化剂,利用N2吸脱附、H2-TPR、XRD、NH3-TPD等表征了催化剂的结构性质.研究了催化剂在生物质基合成气一段法制取液态烃燃料的应用.相比于CuCoMn催化剂,加入分子筛的双功能催化剂均不同程度地提高了液体烃燃料的选择性及收率,且收率按顺序递减呈CCMZSM-5>CCM-SAPO-34>CCM-Y>CCM-MCM-41.同时,共沉淀法制备的CuCoMn-ZSM-5(20wt%,Si/Al=100)具有最佳的CO转化率(76%)及液体产物收率(30%0.相比于CuCoMn氧化物,双功能催化剂的比表面及孔容均得到提高.CCM-ZSM-5具有适中的微孔尺寸和中等强度的酸性,增加CCM-ZSM-5中ZSM-5含量或降低ZSM-5中的Si/Al比,均有利于提高酸性位的数量,主要是较弱的酸性位.而共沉淀法制备的CCM-ZSM-5具有更好的金属分散性及还原性能.更多还原

【Abstract】 A series of bifunctional catalysts composed of a component for higher alcohol synthesis(CuCo Mn oxides, CCM) and an acidic zeolite(SAPO-34, ZSM-5, Y, MCM-41) were prepared for production of liquid hydrocarbon directly from a bio-syngas through a one-stage process. The effects of zeolite type, zeolite content, Si/Al ratio and preparation method on catalyst texture and its reaction performance were investigated. Higher selectivities and yields of liquid products were obtained by using bifunctional catalysts. The yields of liquid hydrocarbons decreased in the order CCM-ZSM-5>CCM-SAPO-34>CCM-Y>CCM-MCM-41. CCM-ZSM-5(20wt%, Si/Al=100) prepared by coprecipitation method displayed the optimal catalytic performance with the highest CO conversion(76%) and yield of liquid products(30%). The catalysts were characterized by N2adsorption/desorption, NH3-TPD,XRD, and H2-TPR analysis. The results showed that higher specific surface areas and pore volumes of bifunctional catalysts were achieved by adding zeolites into Cu Co Mn precursors.Medium pore dimension and moderate acidity in CCM-ZSM-5 were observed, which probably resulted in its excellent reaction performance. Additionally, a higher number of weaker acid sites(weak and/or medium acid sites) were formed by increasing ZSM-5 content in CCM-ZSM-5 or decreasing Si/Al ratio in ZSM-5. It was also seen that metal dispersion was higher and reducibility of metal ions was easier on the CCM-ZSM-5 catalyst prepared by coprecipitation. The higher alcohols-to-hydrocarbon process provides a promising route to hydrocarbon fuels via higher alcohols from syngas or biobased feedstocks.更多还原